1. Field of the Invention
This invention relates to an isolated, recombinant nucleic acid comprising a sequence that encodes bovine interferon-λ3 (boIFN-λ3), an antiviral pharmaceutical composition comprising a vector containing the isolated, recombinant nucleic acid encoding bovine interferon-λ3 (boIFN-λ3) and additional antiviral pharmaceutical compositions comprising a combination of a vector containing the isolated, recombinant nucleic acid encoding bovine interferon-λ3 (boIFN-λ3) and a vector containing other biotherapeutics such as the isolated, recombinant nucleic acid encoding porcine Type I interferons (poIFN-α/β), or the isolated, recombinant nucleic acid encoding bovine Type I interferons (boIFN-α/β), or the isolated, recombinant nucleic acid encoding foot and mouth disease virus (FMDV) antigen, wherein the compositions are capable of inducing systemic antiviral activity, specifically anti-foot and mouth disease virus (anti-FMDV) activity and of inducing up-regulation of specific gene expression in vivo, and thereby acting to delay and reduce severity of foot and mouth disease (FMD) and to the method of treating bovines, swine, goats, and sheep with the antiviral compositions of the invention in order to reduce or prevent the degree or rate of infection by FMDV and to reduce the severity of FMD or any symptom or condition resulting from infection by the FMDV in the treated animal as compared to an untreated infected animal.
2. Description of the Relevant Art
Foot-and-mouth disease virus (FMDV) is the etiologic agent of one of the most devastating diseases that affects cloven-hoofed livestock. Infection with FMDV causes an acute disease that spreads very rapidly and is characterized by fever, lameness and vesicular lesions on the feet, tongue, snout and teats, with high morbidity but low mortality (Grubman and Baxt. 2004. Clinical Micro. Rev. 17:465-493). With the exception of North America, Western Europe and Australia, FMD is enzootic in the rest of the world where disease control is achieved by inhibition of animal movement, slaughter of infected and in contact animals, disinfection of contaminated premises and vaccination with an inactivated whole virus antigen. However, use of this vaccine is not recommended in FMD free-countries due to technical limitations in differentiating vaccinated from infected animals and to the more severe trade restrictions for animals or animal products from areas where the vaccine is used, as established by the International Organization of Animal Health programs (World Organization for Animal Health (OIE). Foot and Mouth Disease. OIE Terrestrial Animal Health Code. Chapter 8.5 (2010). In recent years the OIE has recognized that, to be successful, FMD control programs should include the use of antivirals and/or immunomodulatory molecules in addition to newly developed marker vaccines (Scudamore and Harris. 2002. Rev. Sci. Tech. Off. Int. Epiz. 21: 699-710).
In all vertebrates, expression of interferons (IFNs) constitute the first line of defense against viral infection and, indeed, administration of IFNs as biotherapeutics has been effective in controlling several viral infections (Basler and Garcia-Sastre. 2002. Int. Rev. Immunol. 21: 305-337; Fensterl and Sen. 2009. Biofactors 35:14-20). In the case of FMDV, we have previously demonstrated that treatment of bovine, porcine and ovine cells with type I or type II IFN dramatically inhibits viral replication (Chinsangaram et al. 1999. J. Virol. 73: 9891-9898; Chinsangaram et al. 2001. J. Virol. 75: 5498-5503; Moraes et al., 2007. J. Virol. 81: 7124-7135). Furthermore, swine inoculated with a replication defective human adenovirus 5 vector (Ad5) that delivers porcine IFN-α were sterilely protected when challenged with several FMDV serotypes 24 h post inoculation (Chinsangaram et al. 2001, supra; Moraes et al. 2003. Vaccine 22:268-279; Dias et al. 2010. J. Interferon Cytokine Res. September 28. [Epub ahead of print]). Studies to understand the mechanism by which type I IFN protects swine against FMD have shown that at least some IFN-stimulated genes (ISGs) and migration of immune cells to the sites of infection play a significant role in controlling viral replication in swine (Chinsangaram et al. 1999, supra; de los Santos et al. 2006. J. Virol. 80: 1906-1914; Moraes et al. 2007, supra; Diaz-San Segundo et al. 2010. J. Virol. 84: 2063-2077). However, a similar approach has shown limitations in cattle where only delayed disease and reduced clinical signs have been observed (Wu et al. 2003. J. Interferon Cytokine Res. 7: 359-368).
Recently, a new family of IFNs has been described, type III IFN or IFN-λ (Kotenko et al. 2003. Nat. Immunol. 4:69-77; Sheppard et al. 2003. Nat. Immunol. 4:63-68). These IFNs are related to the type I/II IFN gene families and also to the interleukin 10 (IL10) family of ligands. Within the type III IFN family three structurally related members have been identified in humans, mice and chickens: IFN-λ1 (IL29), IFN-λ2 (IL28A) and IFN-λ3 (IL28B) (Kotenko et al., supra; Sheppard et al., supra; Sommereyns et al. 2008. PLoS Pathog. 4:e1000017; Karpala et al. 2008. J. Interferon & Cytokine Res. 28:341-350). Similar to type I IFN expression, the expression of type III IFN is induced in response to recognition of pathogen-associated molecular patterns and activation of transcription factors, such as nuclear factor κB (NF-κB), IFN regulatory factor-3 (IRF-3) and IFN regulatory factor-7 (IRF-7) (Iversen et al. 2010. J. Virology [Epub ahead of print]). Type III IFN signals through a heterodimeric cellular receptor that is composed of IL28-Rα, a type III IFN-specific subunit and IL10-Rβ, a subunit shared by other IL10 related cytokines. Despite the fact that type I and type III IFNs act on different receptors, they trigger strikingly similar responses through the activation of multiple members of the signal transducer and activator of transcription (STAT) family (Zhou et al. 2007. J. Virology 81:7749-7758). However, expression of the type III IFN receptor in a tissue specific manner, mainly in epithelia, has been proposed as one of the mechanisms evolved by different organisms to possibly prevent and protect themselves from viral invasion through the skin and mucosal surfaces (Sommereyns et al., supra). Although not strictly robust, IFN-λ has been shown to induce protection against several viruses in cell culture, as well as in animal models, including herpes simplex virus type 2 (HSV-2), hepatitis B and hepatitis C (Ank et al. 2006. J. Virol. 80:4501-4509; Robeck et al. 2005. J. Virol. 79:3851-3854; Marcello et al. 2006. Gastroenterology 131:1887-98). Furthermore, a role in modulating the balance of Th1/Th2 immune response has been recently proposed for IFN-λ1 biasing towards a stronger block on Th2 responses (Jordan et al. 2008. Genes and Immunity 8:254-261). No member of the type III IFN family has been described in bovines, and bovine genome sequencing has not provided evidence of predictive sequences for this type of IFN (The Bovine Genome Sequencing and Analysis Consortium et al. 2009. Science 324:522-526). However, very recently a predictive sequence of an IL28B-like mRNA has been deposited in GenBank, but no related literature is available (Accession#XM—002695050).
As discussed, FMDV is highly sensitive to the actions of type I and type II IFNs in vitro and in vivo; however, treatment with these IFNs only conferred partial protection in cattle. Thus, there is an active interest in developing and testing new antivirals with proven efficacy in this species. Here, we report the identification and cloning of a member of the bovine (bo) type III IFN family, boIFN-λ3, and the characterization of its anti-FMDV properties.
Adjuvant activity of IFNs has been shown against various viral infections including FMD (Toporovski et al. 2010. Expert. Opin. Biol. Ther 10:1489-1500; Cheng et al. 2007. Vaccine 25: 5199-5208; de Avila Boton et al. 2006. Vaccine 24: 3446-3456). Most of these studies included type I and type II IFNs. A satisfactory response against FMD was obtained in swine; therefore, similar results are expected in cattle (de Avila Boton et al, supra). Recent studies have shown that type III IFN displays adjuvant activity in humans (Morrow et al. 2009. Blood 113:5868-5877).